1. Field of the Invention
The present invention relates to a photoelectric conversion apparatus which is used in a copying machine, an image scanner or the like.
2. Description of the Related Art
A structure having a line sensor in which each pixel array of red (R), green (G) and blue (B) is arranged in a direction perpendicular to an array direction at a predetermined interval is known, as one example of a photoelectric conversion apparatus. An image can be read out by moving the line sensor relatively with respect to a document in a subsidiary scanning direction. In such a photoelectric conversion apparatus, a technology is disclosed as a measure of electrically reducing a color offset in the subsidiary scanning direction, which is shown in Japanese Patent Application Laid-Open No. H05-122542 (hereinafter referred to as Patent Document 1). Patent Document 1 describes a technique for correcting the color offset with a correction unit in the rear stage of a sensor based on a correction factor which has been calculated beforehand at every pixel position.
However, in Patent Document 1, the correction factor according to the color offset quantity is held in an external memory, and when a signal from the sensor is output, an offset correcting unit retrieves the correction factor in the external memory and corrects the signal therewith. However, in this case, the signal processing unit can become complicated due to the correction processing which is performed in a circuit in the rear stage. Alternatively, a circuit scale can be enlarged.
One embodiment of the present invention can suppress the enlargement of the circuit scale of the whole system. Alternatively, the one embodiment can reduce the color offset in the subsidiary scanning direction by a simple control for a control pulse.